1. Field of the Invention
The present invention relates to stethoscopes, and in particular, to devices and methods for disinfecting them.
2. Description of Related Art
Stethoscopes are used by medical professionals to hear faint sounds inside a patient's body cavity; for example, a heartbeat, breathing, and the like. Abnormalities in such sounds can reveal a disease. Stethoscopes are a traditional diagnostic instrument and have been used by medical personnel since the 19th century.
The head of a conventional stethoscope has an open bell on one side and on the other side a relatively wide and shallow chamber covered with a diaphragm. The side selected may be chosen based on the audio spectrum or other characteristics of the sound source. The stethoscope head communicates acoustically with a flexible tube that is joined through a Y union to a pair of tubes that connect to two earpieces in order to deliver binaural sound. The rims of the stethoscope's diaphragm and bell are typically circular, although in some cases a rim may be almond-shaped.
A risk of spreading infection with the stethoscope exists because of its routine use by professionals throughout the day on multiple patients. Nosocomial infections are a significant known cause of hospital morbidity and mortality. To prevent the spread of infection, some professionals will wipe the head of their stethoscope after each use with a pad soaked in isopropyl alcohol. Also, the depth of the bell on the head of the stethoscope makes effective wiping difficult. A simple and cost effective way to prevent these infections from spreading would be highly valuable to health care professionals and their patients.
One study recommends as effective cleaning solutions for stethoscopes 70% isopropyl alcohol or hypochlorous acid in solution. Africa-Purino, Edwin and Coronel, Stethoscopes: A Potential Source of Nosocomial Infections, The Philippine Journal of Microbiology and Infectious Diseases; Vol 29, No. 1, Topic 2 (January-March 2000). This study found that stethoscopes could harbor Staphylococcus aureus and other harmful and potentially lethal bacteria. This study also found that only about X % of medical professionals actually wipe the stethoscope after each use.
See also U.S. Pat. Nos. 3,292,993; 3,342,544; 3,765,573; 3,943,951; 4,997,629; 5,074,322; 5,641,464; 6,018,835; 7,282,177; and 7,282,186, as well as US Patent Application Publication No. 2004/0258560.